The present disclosure is directed to a high pressure gas collection system and more particularly to a system which collects samples to be taken to a laboratory so that the gas samples can be tested and an assay provided. It is especially important to do this in the buying and selling of expensive gaseous products which are manufactured in great volumes by very large petrochemical plants. More particularly, the system collects a sample without permitted out-gassing or other bleeding to atmosphere or loss of components in the course of collection and transfer. Typically, a gas sample is a mix of several different gases which may have different vapor pressures where some may leak more or less readily through seals to atmosphere. U.S. Pat. No. 5,345,828 of the present inventor sets forth a process plant sample collection system. In that, a process is trapped so that a sample can be obtained. The sample is delivered through a buffer tank 42 and is ultimately accumulated in a sample container 20. The sample container is isolated with a septa across the narrow neck of the container. While this system has met with significant success, it is limited in that it is best used for liquids which are dropped to a pressure near atmospheric pressure. Moreover, it operates in a system which includes a nitrogen purge gas. This helps assure that the system is kept clear. The nitrogen purge step is avoided by the high pressure gas delivery system of this disclosure.
More recently, U.S. Pat. No. 5,396,812 issued and shows certain elements of the same structure. Again, it is a successful system which particularly finds use and application in handling of materials which are brought near to atmospheric pressure. It is particularly important to note that is has a closed system where the sample is isolated with nitrogen input to the sample collection system. Notwithstanding the incorporation of the nitrogen gas isolation, the system works quite well to provide isolated samples, and the isolated samples are received in the appropriate storage container. This storage container can maintain a modest level of pressure on the interior.
Both of the foregoing sample systems are quite successful. Moreover, both are particularly effective for collecting samples where the fluid in the system is not highly pressured and where the sample is liquid. The present disclosure is directed to an entirely different system. It is particularly useful for a sample source where the material in question typically is provided at elevated pressure or elevated temperature or both. While there is a superficial structural similarity between the prior systems and this disclosure in the implementation of a two position, six port valve, the handling of the sample is significantly different. This system is especially useful for fluids which are substantially in the vapor phase. In the vapor phase, sample capture and delivery into a container is more difficult. In the vapor phase, there is the possibility of the gas seeping through a perforated septa or other seal membrane closing a container. In the present disclosure, the sample can be provided at an elevated or highly elevated pressure, temperature or both and can be captured in a container without vapor loss so that it can be taken to a laboratory for testing.
The present disclosure sets forth a six port, two-way valve which enables a sample to be removed from a flowing process such as a petrochemical plant and in particular part of the plant where the flowing fluids are at extremely high pressures or temperatures, and often at both high pressure and temperature. Through the use of the present disclosure, an individual closed sample chamber is installed in the system. It is first opened within the system and any gases which may be residual in the container are purged through the system to atmosphere preferably by bleeding off to atmospheric pressure through a check valve which connects with an optional flare. Bleeding through the flare assures that the discharge is appropriately combusted for safety. The system also incorporates a sample cylinder having two ports with isolation valves at the two ends of the sample cylinder. The two ports also connect with isolation valves and then connect there beyond to quick disconnect fittings. The quick disconnect fittings enable the disconnection of the sample cylinder after it has been filled to high pressure. The isolation valves enable isolation of the system from the sample container so the sample is not diluted or otherwise mixed with unintended gases from atmosphere. The container connected isolation valves and quick release fittings also enable the isolation of the sample container so that the sample container can be carried in a truck or other vehicle. Even though the sample cools within the sample container, and the pressure drops accordingly, the sample remains isolated for delivery to the testing facility. By using multiple sample containers (tagged and labeled with sample date and time), sample portability enables testing notwithstanding the high pressure in the product system. The present disclosure has the advantage that it is a relatively simple system and yet it is particularly able to operate to fill sample containers in scheduled order.
Directing attention now to the present disclosure, it sets forth both an apparatus and method for use of the apparatus with a view of obtaining a sample. The sample is provided from a process which is connected to the present apparatus through a two-position, six-port valve. By appropriate routing, a sample container is filled. The sample container is provided with two ends so that fluid flows fully through it. The container has two ends connected with isolation valves. The valves assure container portability without leakage. Dismounting is done by two quick release connections.
In summary, the present disclosure sets forth a six-port, two-way valve having a single valve structure. This enables switching of the sample container into and out of a connected control valve so that processed fluid can be delivered into and out of the sample container. The sample container is preferably provided with two fittings. The sample container is an elongate cylinder having fittings at opposite ends, and the two opposite ends are each provided with isolation valves and quick disconnect fittings. This defines a portable structure which can be carried to another location for testing. This enables the contents of the sample container to be isolated without leakage so that the material can be tested at a testing laboratory.